[monday_]

I have been thinking about adding conductive traces a-la PCB to 3D prints in a DIY setting for a while. Obviously, conductive filaments exist - but they are not remotely in the same category as copper.

My initial hope was that doping PLA, PETG or some other material with a conductor and then applying strong variable magnetic field near the print head to force creation of conductive domains while the filament is amorphous and hot. This turned out to be not feasible, as O3 explained to me repeatedly, over hours of chats.

A simpler and surprisingly workable solution appears to be adding a second printing head loaded with tin. Tin is not as good as copper - but it's still leagues ahead of conductive filaments. To offset the poor conductivity you can use thin, but very broad traces.

A speculative approach would work like this:

1. Print PETG layers using a regular filament, but leave "baths" for tin traces. A bath should be an opening at least 2-3 millimeters tall, to account for the surface tension.

2. After N layers, fill the baths from the tin head. Tin melting point is near PETG, but it would cool rapidly and, hopefully, weld to the plastic.

This way you could probably integrate a pcb into a print. I haven't tried that, but i recall people actually trying to print with tin - so that part is at least not a complete fantasy.

[weq]

Apply PCB mask to copper sheet then laser etch it. UV printing has some more promise here, i just dont think FDM 3d printing is gonna be the solution.

[torginus]

This, I think non-planar PCBs are an incredibly niche thing, and very rarely necessary. you can just run wires/connectors between multiple PCBs, it's no biggie if your prototype needs some manual assembly.

Fiber laser etching is the way to go, the required equipment is already below $2000, and the process is quite simple. Additionally manufacturing copper/aluminium is next to impossible at home, considering their melting points.

You could even use a pre-masked copper plate (which is less reflective than copper), so your PCB would come with a mask.